Pneumatic springing of vehicles



F. S. FARNSWORTH PNEUMATIC SPRINGING 0F VEHICLES.

APPLICATION FILED APR. 10, 1920- Patented Jan. 4,1921.

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UNITED STATES .ATENT orriea.

PNEUMATIC SPRINGING OF VEHICLES.

Specification of Letters Patent.

Patented Jan. 4, 1921.

Application filed April 10, 1920. Serial No. 372,976.

To. all whom it may concern.

Be it known that I, FRANK SMEDLEY FARNswonTH, a subject of the King ofGreat Britain and Ireland, residing at No. l Darwin Terrace, in thecounty borough of Derby England, have invented new and use fulImprovements in the Pneumatic Spring ing of Vehicles, of which thefollowing is a specification.

The object of my invention is to improve the springing of vehicles.

Referring'to the drawings which form a part of this specification Figure1 is an end view of the device, with the end wall or cover removed.

Fig. 2 is a section taken approximately on the line 2-2 of Fig. 1.

Fig. 3 illustrates one form of application of my spring to a motor carchassis; this figure being drawn to a greatly reduced scale. 4

In carrying out myinvention I employ a metal cylinder a truly turned onthe inside diameter and fitted with covers Z) at each end. Both thesecovers may be bolted to the cylinder body or one cover may be cast solidtherewith.

Through the center of the cylinder a and covers 6 is placed a turnedshaft 0 of suitable diameter. The bearings d for said shaft are formedin the cylinder covers Z). Fixed solidly to the shaft 0 and at rightangles to it is a vane or wing e which exactly fits the space betweenthe shaft 0 and the walls of the cylinder (1 and also is a fit betweenthe covers 6. If the shaft and vane were now revolved the whole of theinterior of the cylinder a would be swept. In my spring the shaft 0 isnot intended to revolve in a. complete circle but only through a portionthereof; it is prevented from revolving in a complete circle by a stop 7which is rigidly connected to the cylinder a and completely fills thespace between the shaft 0 and the walls of the cylinder and also betweenthe cylinder covers 5. The shaft 0 and vane 6 can now only be turned ineither direction until the vane e meets the stop 7. (The above describedarrangement is similar to the construction of an ordinary wing orsemi-rotary pump minus valves and ports).

The vane e is now turned until it is opposite the stop 7", the twoforming a diameter across the cylinder and dividing it into two parts.

Inflatable pneumatic bags 9 of rubber, rubber and canvas, or othersuitable material are placed on each side of the vane e filling up wheninflated (through valves 7b) the space between the vane c and the stopIt will now be seen that thesha-ft c carrying the vane e cannot beturned in either direction without compressing one or other of thepneumatic bags 9 thus a perfect spring is formed which may have anydegree of strength according to the pressure of infiation of thepneumatic bags 9. If the latter are made of rubber or other extensiblematerial or rubber and canvas, of a suitable shape to'allow of expansionto follow up any movement of the vane c the re-action or rebound of thespring is materially deadened and very efficient springingof the vehicleis the result.

One method of providing means of expansion of the pneumatic bags 9 whenmade of rubber and canvas or other non-extensible material is shown inFig. 1 where the vane e is made of a section to form depressions in theends of the pneumatic bags 9.

When the vane e is turned in either direction the depression in theendof the pneumatic bag on one side of the vane is rendered deeper whilethe depression in the end of the pneumatic bag on the other side of thevane becomes shallower until at the limit of expansion it may assume aconvex shape.

In the form of the device illustrated, the pneumatic bags are made up ofa plurality of sections of spherical or cylindrical shape according tothe amount of expansion required. These sections would of course beconnected together to allow of inflation, and when placed in positionwould assume a segmental or triangular cross section but when the vane cwas moved circumferentially (thus allowing space for expansion) theywould assume more or less their natural spherical or cylindrical shape.

In heavy vehicles if it is desired to limit the movement of the springthe vane fixed to the shaft may be made a complete dlameter instead of aradius of the cylinder but in this case two stops fixed across adiameter would be necessary and four pneumatic bags, the arrangement ofwhich is obvious.

It must be distinctly understood that there is no connection between thepneumatic bags on the two sides of the vane, the bag or series of bagson either side forming a distinct spring in itself.

One method of applying my spring to a motor car chassis is shown at Fig.3.

The body of the spring that is the cylinder at and covers 6 containingthe pneumatic bags is rigidly connected to or forms part of the chassis.On the outer ends of the shaft 0 carrying the vane e is keyed one end ofa lever, leaf spring or the like 7' of suitable length the other end ofwhich is directly connected to the axle Z3 carrying the road wheels Z.By this construction any movement of the axle caused through road shocksis communicated directly to the pneumatic bags and is absorbed by thembefore reaching the body of the vehicle.

My springing arrangement as above described may be used alone or inconjunction with ordinary leaf springs of cantaliver, elliptical orsemi-elliptical design.

If the pneumatic bags should leak through any cause positive stops mayeasily be arranged on the cylinder covers 5 to limit the movement of thelever or leaf spring and will carry the weight of the vehicle withoutrisk of accident until the pneumatic bags can be renewed.

Having now descrlbed my invention what I claim as new and desire tosecure by Letters Patent is 1. A pneumatic spring for vehicles,comprising a cylindrical casing adapted to be secured to the body of thevehicle, a shaft mounted for rotation in said casing, a radial bladesecured to said shaft and rotatable therewith, said blade extending fromsaid shaft to the sidewall of the casing, a radial stop secured in thecasing and extending from the shaft to the sidewall of the casing, aplurality of pneumatic cushioning members within the casing at bothsides of said blade and stop, and means for transmitting motion from theaxle of the vehicle to said shaft.

2. A pneumatic spring for vehicles, comprising a cylindrical casingadapted to be secured to the body of the vehicle, a shaft mounted forrotation in said casing, a radial blade secured to said shaft androtatable therewith, said blade extending from said shaft to thesidewall of the casing, a radial stop secured in the casing andextending from the shaft to the sidewall of the casing, a plurality ofpneumatic cushioning members within the casing at both sides of saidblade and stop, and means for transmitting motion from the axle of thevehicle to said shaft, said blade having at each sidethereof a convexprojection for compressing said pneumatic members,

In testimony whereof I have signed my name to this specification.

FRANK SMEDLEY FARNSWORTH.

